Rabionet Mariona, Gorgas Karin, Sandhoff Roger
Lipid Pathobiochemistry Group within Department of Cellular & Molecular Pathology, German Cancer Research Center (dkfz.), Heidelberg, Germany.
Department of Anatomy and Medical Cell Biology, University of Heidelberg, Germany.
Biochim Biophys Acta. 2014 Mar;1841(3):422-34. doi: 10.1016/j.bbalip.2013.08.011. Epub 2013 Aug 27.
The epidermis and in particular its outermost layer the stratum corneum provides terrestrial vertebrates with a pivotal defensive barrier against water loss, xenobiotics and harmful pathogens. A vital demand for this epidermal permeability barrier is the lipid-enriched lamellar matrix that embeds the enucleated corneocytes. Ceramides are the major components of these highly ordered intercellular lamellar structures, in which linoleic acid- and protein-esterified ceramides are crucial for structuring and maintaining skin barrier integrity. In this review, we describe the fascinating diversity of epidermal ceramides including 1-O-acylceramides. We focus on epidermal ceramide biosynthesis emphasizing its metabolic and topological requirements and discuss enzymes that may be involved in α- and ω-hydroxylation. Finally, we turn to epidermal ceramide regulation, highlighting transcription factors and liposensors recently described to play crucial roles in modulating skin lipid metabolism and epidermal barrier homeostasis. This article is part of a Special Issue entitled The Important Role of Lipids in the Epidermis and their Role in the Formation and Maintenance of the Cutaneous Barrier.
表皮，尤其是其最外层的角质层，为陆生脊椎动物提供了一个关键的防御屏障，可防止水分流失、抵御外源性物质和有害病原体。这种表皮渗透屏障的一个重要需求是富含脂质的板层基质，它包裹着无细胞核的角质形成细胞。神经酰胺是这些高度有序的细胞间板层结构的主要成分，其中亚油酸酯化和蛋白质酯化的神经酰胺对于构建和维持皮肤屏障完整性至关重要。在这篇综述中，我们描述了包括1-O-酰基神经酰胺在内的表皮神经酰胺的迷人多样性。我们重点关注表皮神经酰胺的生物合成，强调其代谢和拓扑学要求，并讨论可能参与α-和ω-羟基化的酶。最后，我们转向表皮神经酰胺的调节，重点介绍最近描述的在调节皮肤脂质代谢和表皮屏障稳态中起关键作用的转录因子和脂质传感器。本文是名为“脂质在表皮中的重要作用及其在皮肤屏障形成和维持中的作用”的特刊的一部分。
